This sounds like a severe restriction on the cold water line prior to the H/W tank and supply line to the kitchen. I would personally check the nearest valve on the cold water supply leading to this tank and possibly isolating it from the system. The remove the bonnet and check o make sure the Gate/washer (if a globe valve) had be dislodged in the partially closed position.
Just let the tank cool down 1st so you don’t get back feed and get burned and shut off the water to this valve.
[Edited by SylvanLMP on 25 May 2000]